Pyridylium-s-triazines for regulating plant growth

ABSTRACT

2,4-bis-pyridylium-s-triazines of the formula   WHEREIN R1 represents hydrogen, lower alkyl, lower haloalkyl, NH2, OH, phenyl, 4-pyridyl, N&#39;&#39;-methyl-4&#39;&#39;-pyridylium, R2 and R3 each independently represent alkyl, alkenyl, an alkyl radical substituted by halogen, alkoxy, alkylthio, cyano, alkoxycarbonyl, and X represents the anion of an inorganic or organic acid or a trivalent halogen anion, are growth regulating agents which produce increases in yield or quality in crop plants or which facilitate harvesting.

United States Patent Fischer 1 Aug. 26, 1975 [54] PYRIDYLIUM-S-TRIAZINES FOR 3,544,570 12/1970 Timmler et a]. 71/93 REGULATING PLANT GROWTH Primary ExaminerElbert L. Roberts [75] Inventor g ll f j Bottmmgen Assistant Examiner-Catherine L. Mills zer an Attorney, Agent, or Firm-Frederick H. Rabin [73] Assignee: Ciba-Geigy Corporation, Ardsley,

N.Y. [57] ABSTRACT [22] Fil d; O t, 25, 1974 2,4-bis-pyridylium-striazines of the formula App]. No.: 517,988

Related US. Application Data [30] Foreign Application Priority Data Dec. 22, 1971 Switzerland 18819/71 [52] US. Cl. 71/74; 71/76; 71/93 [51] Int. Cl. A01N 9/22 [58] Field of Search "ll/93, 74, 76

[56] References Cited UNITED STATES PATENTS 3,498,981 3/1970 Culbertson 7l/93 3,5l0,483 5/1970 Trepanier 7l/93 wherein R represents hydrogen, lower alkyl, lower haloalkyl, NH OH, phenyl, 4-pyridyl, N '-methyl-4'- pyridylium, R and R each independently represent alkyl, alkenyl, an alkyl radical substituted by halogen, alkoxy, alkylthio, cyano, alkoxycarbonyl, and X represents the anion of an inorganic or organic acid or a trivalent halogen anion, are growth regulating agents which produce increases in yield or quality in crop plants or which facilitate harvesting.

22 Claims, No Drawings PYRIDYLlUM-S-TRIAZINES FOR REGULATING PLANT GROWTH CROSS-REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of my application Ser. No. 316,948, filed Dec. 20, 1972, now US. Pat. No. 3,855,220 and a continuation-in-part of my application Ser, No. 460,405, filed Apr. l2, 1974.

The present invention relates to quaternary salts which regulate plant growth and in particular-with desiccating, defoliating and herbicidal action, a process for their manufacture, also to plant regulators and to a method of regulating plant growth, chiefly the desiccation and defoliation of parts of plants above the soil, and to a method of combating weeds which comprises the use of these quaternary salts as active substances. The term plant growth is to be understood as encompassing all stages of plant growth and development. The new quaternary salts correspond to the formula I:

wherein R represents hydrogen, lower alkyl, lower haloalkyl, NH OH, phenyl, 4-pyridyl, N-methyl-4'- pyridylium, R and R each independently represents alkyl, alkenyl, an alkyl radical substituted by halogen, alkoxy, alkylthio, cyano, alkoxycarbonyl, and X represents the anion of an inorganic or organic acid.

The alkyl radicals of the formula I are straight-chain or branched radicals with l to 8 carbon atoms, e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec.butyl, tert. butyl, n-pentyl, n-hexyl and n-octyl and the isomers of the alkyl radicals with 5 to 8 carbon atoms. The lower, straight-chain or branched alkyl radicals in particular, i.e. those with l to 4 carbon atoms, form the alkyl moiety of alkoxy and alkylthio radicals. Lower haloalkyl radicals are radicals with l to 4 carbon atoms which can be monoor polysubstituted by halogen, especially fluorine. The CF group is to be particularly mentioned. Alkenyl radicals can be straightchain or branched and possess 3 to 7 carbon atoms. Suitable examples are propenyl, butenyl, pentenyl, hexenyl and heptenyl; preferred are the ally] and methallyl radicals. For the symbol X as the anion of an inorganic or organic acid there may be considered, for example, the anions of the following acids: hydrohalic acids, such as hydrochloric, hydrobromic acid or hydroiodic acid, phosphoric acid, thioand dithiophosphoric acid, sulphuric acid, fluoroboric acid (HBF perchloric acid, alkylsulphuric acid, such as methylor ethylsulphuric acid, arylsulphuric acids, such as benzenesulphonic acid or p-toluenesulphonic acid, naphthoic acids, ben zoic acid, halobenzoic acids, acetic acid, haloacetic acids, aminoacetie acid, propionic acid, halopropionic acids, butyric acid, lactic acid, stearic acid, aliphatic dicarboxylic acids, such as oxalic acid, tartaric acid, fluorosulphuric acid. X can also represent a trivalent halogen anion preferably 1 Br Br Cl, l Br' or 81 21 Preferred compounds of the formula la wherein R represents hydrogen, lower alkyl, halosubstituted lower alkyl, NH OH, phenyl, 4-pyridyl. As quaternising agents for the complete or stepwise alkylation (or alkenylation) of the pyridyl radicals there are used accordingly one or two molar equivalents of the compound R -X or one molar equivalent of each of the compounds of the formulae Rg-X and R3X I wherein R and R have the meanings given for the formula l and X represents halogen, alkylsulphonyloxy, alkoxysulphonyloxy, arylsulphonyloxy, fluorosulphonyloxy. If R represents OH, it is possible to carry out the reaction in the presence of one molar equivalent ofa strong base, such as an alkali alcoholate. If R." in its significance of 4-pyridyl is to be converted into the 4-N-methylpyridylium radical, it is also necessary for the 4-pyridyl radical to be quaternised, optionally in an independent reaction, with methyl halide or dimethyl sulphate.

[t is advantageous to carry out the quaternisation in the presence of a solvent or diluent which is inert towards the reactants, such as an aromatic hydrocarbon, for example benzene, toluene or xylene, a chlorinated hydrocarbon, e.g. chlorobenzene, an N-alkylated acid amide, such as dimethyl formamide, sulphoxides, such as dimethyl sulphoxide, nitriles, such as acetonitrile, ketones, such as acetone or methyl ethyl ketone, alcohols, in particular lower alkanols, ethers and ethereal compounds, water, or mixtures of such solvents. The quaternisation temperatures are between 20C and +250C. The reaction times are from minutes to several days and are dependent to a considerable extent on the reactivity of the reactants and the solvent used. The quaternary salts obtained are optionally reacted to exchange the anion of a possibly phytotoxic acid for other non-phytotoxic inorganic or organic acids. For example, the halogen anion of a resulting quaternary salt can be easily exchanged for the anion of any desired inorganic or organic acid by a. conversion of the halide into the hydroxide and subsequent neutralisation with the corresponding acid,

b. treatment of the halide or hydroxide with anion exchanger, or, if an iodine or bromine ion is present,

0. reaction with 1 to form 1 or with Br to form Br The intermediate products of the general formula 11 can be manufactured by several process variants:

1. Either one mole of 1.1 (4-amidinopyridine pyridine) or 1.2 of a 4alkoxycarbonimidoyl-pyridine (=4-carbamimidoylis reacted in the presence of an acylating agent in a single or multi-step process with 1 mole of 4- amidinopyridine [J. org. Chem. 30, 707 (1965); J. Synth. Org. Chem. 27, 551 (1969)],

2. one mole of 2.1 urea, guanidine or amidine of the formula in one of the possible isomeric forms, or one mole of 2.2 a compound of the formula R "'CN, wherein R,"' represents lower alkyl, phenyl or 4-pyridyl, is reacted with two moles of 4-cyanopyridine.

The reactions of types 1 or 2 can be carried out in the presence, or absence, ofa catalyst. Type 2 is preferably carried out in the presence of a catalyst. Suitable catalysts are acids, such as mineral acids (hydrochloric acid, sulphuric acid) or Lewis acids, (AlCl ,ZnCl BF also bases such as tertiary amines, alkali hydroxides, alkali alcoholates, sodium hydride and others. The choice of catalyst is dependent in each case on the reactants.

Depending on the particular reaction, suitable acylating agents are corresponding carboxylic acids, esters, amides, chlorimonium slats, amidines and their salts, alkyl cyanides, aryl cyanides, acid halides, acid anhydrides, ortho-esters, aminoacetals, cyanogen halide, phosgene etc. i

The starting materials for reaction type 1 or 2 are known or can be-prepared by known methods.

For example, 4-amidinopyridine and its salts are known from J.Am.Chem.Soc, 75, 1933-1942 (1953) and J. Org.Chem. 19, 753-757 (1954). This compound is obtained by converting 4-cyanopyridine with an alkanol, such as ethanol, into the corresponding iminoether (imido ester) and heating this latter with aqueous ammonium chloride solution.

The most important compounds of the formula 11 which are used as intermediate products for the quaternary salts of the formula I and wherein R' represents hydrogen, are manufactured preferably by reacting 2 molar equivalents of 4-amidinopyridine with 1 molar equivalent of a formylating agent in the absence of a solvent. Examples of suitable formylating agents are: formic acid, formamide, esters of formic acid, dialkyl formamide, chloro-N,N-dimethylformamidinium chloride, formamidine, dimethylamino-bis(alkoxy)- methane, s-triazine or the formyl chloride which is formed as an intermediate from C0 and HCl. A very advantageous formylating agent is the 2- azapropenylidene ammonium salt of the formula (cf. Angewandt Chemie 72,959 [1960]), which is obtained by reacting cyanuric chloride with dimethyl formamide at about 50C.

The reaction of 4-amidino-pyridine or the salts thereof with an azapropenylidene ammonium salt is carried out at temperatures between C and 200C in the presence or absence of a solvent or diluent.

The compounds of the formula 11, in which R," represents alkyl, halosubstituted lower alkyl or phenyl, which are used as intermediate products for the quaternary salts of the formula I, are preferably manufactured by reacting 2 molar equivalents of 4-amidinopyridine hydrochloride with 1 molar equivalent of an acid anhydride (R,"CO-) 0 in the presence ofa mild base, or with 1 molar equivalent of a salt of the formula R,"- COO alkali. The reaction temperatures lie between 50C and C. [Chem. Ber. 11, 4 (1878); ibid. 23,161 (1890)].

The compounds of the formula 11, wherein R," represents OH or NH which are used as intermediate products for the quaternary salts of the formula I, are manufactured preferably by reacting 4-cyanopyridine with urea or guanidine (or guanidine hydrochloride) in the presence of a strong base, such as an alkali alcoholate, sodium or sodium hydride, in a solvent (alkanol, di-

methyl sulphoxide). [J.Am.Chem.Soc. 81, 905 9)]- The intermediate product 2,4,6-tris(4-pyridyl)-striazine for the manufacture of corresponding quaternised salts according to formula I is manufactured by trimerisation of 4-cyanopyridine in the presence of sodium hydride in the melt. [Chem. Commun. 1971, 498].

For example, the following most important intermediate products of the formula 11 can be manufactured by the indicated methods:

as well as the intermediate product of the formula 35 -NO-%N 1 m.p'. 172C mp. 172C The following Examples illustrate the individual process variants for the manufacture of compounds of the formula 1.

EXAMPLE 1 a. 416 g of 4-cyanopyridine (4.0 moles) were dissolved in 1600 ml of methanol, then 4 g of sodium in 400 ml of dry methanol were added at C. The temperature rose to 30C and was then kept at 2830C with an ice bath. The reaction mixture was stirred for 4 hours, then 235.6 g of ammonium chloride in 400 ml of water were added. The temperature was kept continuously at 2830C. The reaction mixture, which turned clear after some time, was stirred overnight at room temperature and a practically colourless precipitate formed. Yield: 540 g of 4-amindino-pyridine hydrochloride (m.p. 248250C).

h. 97 g (0.615 mole) of 4'-amidinopyridine hydrochloride and 127.5 g (0.778 mole) of3-dimethylamino- 2-azaprop-2-en-ylidene-dimethylammonium chloride were thoroughly mixed in a mortar. The reaction mixture was heated for 2 hours to 120C. in the course of which it became viscous. It was subsequently heated for 18 hours to 140C. The congealed reaction mixture was then triturated in small amounts at a time with 1000 ml of water. The precipitate was filtered and washed with distilled water until the washings ran free from chloride.

Yield: 65.4 g of 2,4-bis-(4pyridyl)-s-triazinc (m.p. 186 1 87C).

0. 23.5 g of 2,4-bis-(4'-pyridyl)s-triazine were dissolved in 500 ml of absolute methanol. To this solution were added 31.2 g of methyl iodide and the mixture was stirred for about 14 hours at C under reflux. It was then cooled to 0C and the residue was filtered off.

Yield: 41.9 g of 2,4-bis-(N-methyl-4-pyridylium)-striazine iodide (m.p. 248-25lC).

d. 62 g (0.263 mole) of 2,4-bis-(4-pyridyl)-s-triazine were dissolved in 800 ml of methylene chloride in an agitator flask. Then CH -O-SO -F was added dropwise at room temperature over about 30 minutes. The temperature was kept at 3035C with an ice bath. A grey precipitate formed. Stirring was continued overnight at room temperature and the batch was filtered, to give 120.4 g of 2,4-(N-methyl-4'-pyridylium)-striazinefluorosulphate (m.p. 220C, with decomp.).

e. 225 g of 2,4-bis(4-pyridyl)-s-triazine and 228 g of methyl bromide were heated with 1000 ml of methanol for 52 hours to 80C in a pressure autoclave. Yield: 320 g of 2,4-bis(N'-methyl-4-pyridylium)-s-triazinedibromide (m.p. 260C, with decomp.).

f. 15 g of 2,4-bis(4-pyridyl)-s-triazine, 30 ml of dimethyl sulphate and ml of methanol were heated for 24 hours under reflux. The mixture was concentrated and the concentrate dried in a high vacuum to give 32 g .7 of 2,4-bis-(N-methyl-4'-pyridylium)-striazine-bis-methosulphate in the form of a viscous oil) n,, l .4942

EXAMPLE 2 a. 78.5 g (0.5 mole) of well dried 4-amindinopyridine hydrochloride, 41 g (0.5 mole) of anhydrous sodium acetate and 600 ml of acetic anhydride were charged into an agitator flask. The mixture was stirred for 2 hours at 180C, then excess acetic anhydride was distilled off. The brown, oily residue was treated with 500 ml of water and the resulting voluminous precipitate, which was washed repeatedly with distilled water, was filtered. Yield: 36 g of 2-methyl-4,6-bis-(4- pyridyl)-s-triazine (m.p. 162163C).

b. 55 g (0.22 mole) of 2-methyl-4,6-bis-(4pyridyl)-striazine were suspended in 600 ml of methanol in an ag tator flask. Then 100 ml of methyl iodide were added and the batch was heated for 48 hours under reflux. The batch was cooled to room temperature and the precipitate then filtered, to give 105.3 g of 2-methyl- 4,6-bis(N-methyl-4'-pyridylium)-s-triazine-diiodide (m.p. 285C, with decomp.).

c. 2.5 g (0.1 mole) of 2,4-bis(4-pyridyl)-6-methyl-striazine were dissolved in 25 ml of methylene chloride and 1.1419 g (0.01 mole) of methyl iodide were subsequently added. The reaction mixture was stirred for 24 hours at room temperature, in the course of which a yellow precipitate formed which was filtered off, to give 2.4 g of 2-methyl-4-(4-pyridyl)-6-(N"-methyl- 4"-pyridylium)-s-triazine-iodide (m.p. 284-287C, with decomp.).

d. 1.95 g (0.005 mole) of 2-methyl-4-(4-pyridyl)-6- (N-methyl-4"-pyridylium)-s-triazine-oidide were dissolved in ml of methanol with gentle heating. Then 1.55 g (0.01 mole) of ethyl iodide were added and the reaction mixture was heated for 36 hours under reflux. The solution. which had turned clear. was then concentrated to dryness. The resulting reddish brown product was then taken up in about 150 ml of methylene chloride. and the solution stirred and filtered. Yield: 2.1 g of 2-methyl-4-(N'-ethyl-4'-pyridylium)-6-(N"-methyl- 4"pyridylium)-s-triazine-diiodide (m.p. 250256C, with decomp.).

EXAMPLE 3 a. 15.7 g (0.1 mole) of 4-amidinopyridine hydrochloride and 120 ml of propionic anhydride were charged into a flask. While stirring, 8.2 g (0.1 mole) of sodium acetate (anhydrous) were added and the mixture was heated for 2 hours to 180C. Excess anhydride was distilled off in a high vacuum. The residue, a brown oil, was chromatographed over a silica gel column. A crude product was obtained which was recrystallised from ethyl acetate. Yield: 1.8 g of 2-ethyl-4,5-bis(4- pyridyl)-striazine (m.p. l41144C).

b. 1.1 g (0.00417 mole) of 2-ethyl-4,5-bis-(4- pyridyl)-s-triazine were dissolved in 15 ml of methanol. Then 4.52 g (0.0319 mole) of methyl iodide were added and the mixture was heated for 48 hours under reflux. The reddish brown precipitate was filtered and washed 3 times with about ml of ether. Yield: 1.9 g of 2-ethyl-4.6-bis(Nmethyl-4-pyridylium)-s-triazinediiodide (m.p. 286290C, with decomp.).

c. 8.2 g (0.1 mole) of sodium acetate and 100 g of valeric anhydride were charged into a flask and 4 amidinopyridine hydrochloride was then added. The reaction mixture was stirred for 16 hours at 180C, in the course of which a brown, viscous product formed. This product was taken up in water and the solution was extracted 3 times with 250 ml of methylene chloride on each occasion. The combined extracts were washed with dilute NaHCO solution, dried over magnesium sulphate and evaporated, to yield 101.2 g of a brown oil which was purified by column chromatography. This oil in turn yielded 6.1 g of a product from which, by recrystallisation from isopropanol, there were obtained 1.4 g of 2-n-butyl-4,6-bis 4-pyridy1)-striazine (m.p. l 10-115C).

d. 1.2 g of 2-n-butyl-4,6-bis(4pyridyl)-s-triazine were dissolved in ml of methanol and the solution was treated with 2 ml of methyl iodide. The reaction mixture was heated for 24 hours under reflux, in the course of which a dark red precipitate formed which was filtered off and washed twice with about 30 ml of acetone. Yield: 2,0 g of 2-n-butyl-4,6,-bis(N-methyl-4- pyridylium )-s-triazine-diiodide (m.p. 285-290C, with decomp).

EXAMPLE 4 a. 9.5 g of guanidine hydrochloride were dissolved in 100 ml of absolute alcohol. While stirring and cooling, 2.3 g of sodium were added in small amounts. The precipitated sodium chloride was filtered off. The filtrate was treated with 10.4 g of 4-cyanopyridine and the mixture heated for 15 hours under reflux. It was then cooled to 5C and filtered. The solid product was boiled for 2 hours and filtered once more, to give 3,3 g of 2-amino-4,6-bis(4-pyridyl)-s-triazine (m.p. 310-312C).

b. 22 g of 2-amino-4,6-bis(4-pyridyl)-s-triazine, 15 g of methyl iodide and a mixture of 100 ml of dimethyl sulphoxide and 150 ml of methanol were heated under reflux for 72 hours. The precipitate which formed was filtered hot. Yield: 1 1.8 g of 2-amino-4,6-bis(N- methyl-4-pyridylium)-s-triazine-diiodide (m.p. 300C).

EXAMPLE 5 a. 20.8 g (0.2 mole) of 4-cyanopyridine, 6.1 (0.1 mole) ofurea and 2.4 g o1'NaH(0.l mole) were stirred in 200 ml of dimethyl sulphoxide (absolute) initially for 3 hours at room temperature. then for 33 hours at 1 10C bath temperature. The reaction mixture was concentrated at a bath temperature of 95C. The residue was stirred with 200 ml of acetone and 200 ml of ethanol and filtered off. Yield: 18.3 g of Z-hydroxy- 4,6-bis(4-pyridyl)-s-triazine (m.p. 300C).

b. 2.5 g (0.01 mole) of 2hydroxy-4,6-bis(4- pyridyl)-s-triazine were charged into a flask in 30 ml of methanol. 5 g of methyl iodide were added thereto and the reaction mixture was heated for 30 hours under reflux. The precipitated final product was filtered off and washed twice with about 30 ml of methanol. Yield: 2.7 g of 2-hydroxy-4,6-bis(N-methyl-4'-pyridylium)-striazine-diiodide (m.p. 300C).

EXAMPLE 6 a. 12 g of 4-cyanopyridine were charged into an agitator flask under nitrogen, and 0.2 g of sodium hydride was added. The temperature was kept at 160l65C for 5 hours. The precipitate which formed was filtered off, stirred 3 times with ml of acetone each time and filtered once more. Yield: 9.3 g of 2.4,6-tris(4- pyridyl)-s-triazine (m.p. 340C).

9 g of 2,4,6-tris(4-pyridyl)-s-triazine were heated together with 30 ml of methyl iodide in 30 ml of methanol for 36 hours under reflux. 21.8 g of 2,4,6-tris(N- methyl-4-pyridylium)-s-triazine-triiodide were precipitated from the concentrated solution; mp 260C.

0. 3.12 g (0.01 mole) of 2,4,6-tris(4'-pyridyl)-striazine were partially dissolved in 100 ml of dimethyl sulphoxide. After filtration, the solution was treated with 2.8 g (0.02 mole) of methyl iodide and stirred for 24 hours at 80C. Yield: 1.9 g of 2-(4'-pyridyl)-4,6- bis( N -methyl-4 -pyridylium )-striazine-diiodide (m.p. 310C) in the form of a dark red precipitate.

EXAMPLE 7 a. 8.2 g (0.1 mole) of sodium acetate and 100 g of benzoic anhydride were charged into a flask. Thereto were added 15.76 g (0.1 mole) of 4-amidinopyridine hydrochloride. The mixture was heated for 18 hours to 180C, then taken up in 300-400ml of methanol and undissolved constituents were filtered off. The filter residue was washed free from chloride 3 times with 50 ml of methanol on each occasion and then 4 times with 50 ml of water on each occasion. Yield: 9.4 g of 2- phenyl-4,6-bis(4'-pyridyl)-s-triazine (m.p. 298-300C).

b. 5.96 g (0.042 mole) of methyl iodide were added to a solution of 3.11 g (0.01 mole) of 2-phenyl-4,6- bis(4'-pyridyl)-s-triazine in 100 ml of dimethyl sulphoxide. The reaction mixture was stirred for 24 hours at a bath temperature of 80C, then cooled, to yield 4.8 g of 2-phenyl-4.6-bis(N-methyl-4'-pyridylium)-s-triazine-diiodide (m.p. 310C).

EXAMPLE 8 a. 15.76 g (0.1 mole) of 4-amindino-pyridine hydrochloride were added at 10C to a mixture of 8.2 g (0.1 mole) of sodium acetate and 65 ml of trifluoro-acetic anhydride. The reaction mixture was kept for 2 hours at 100C in a Carius tube and, after it had C cooled, concnetrated in a rotary evaporator. Upon addition of water a brown oil was precipitated from the residue and discarded. The residual solution was extracted 3 times with ml of methylene chloride each time. The combined extracts were washed initially with NaHCO solution and then with water and subsequently dried over magnesium sulphate. The solution was concentrated to yield 1.8 g of 2-trifluoromethy1-4.6-bis(4-pyridyl)-striazine (mp. 152157C).

b. A mixture consisting of 1.5 (0.00495 mole) of 2- trifluoromethyl-4,6-bis-(4-pyridyl)-s-triazine, 30 ml of methanol and 2 g (0.0141 mole) of methyl iodide, was heated for 30 hours under reflux, then concentrated in a rotary evaporator, cooled and filtered. The precipitate was washed with benzene. Yield: 2.26 g of 2- trifluoromethyl-4,5-bis(N-methy1-4-pyridylium)-striazine-diiodide (m.p. 300C).

EXAMPLE 9 47.5 g (0,46 moles) of sodium bromide were dissolved in 4.5 l of water in an open beaker. To this solution was added at room temperature while stirring mechanically, 59 g (0.37 moles) (19 ml) of bromine, which gave a red-brown solution. To this was then added dropwise under stirring at room temperature an aqueous solution of 78 g (0.184 moles) of 2,4 bis (N'- methyl-4-pyridylium)-s-triazine dibromide. A precipitation fell out immediately. Stirring was continued for 10 minutes after all the pyridylium-solution was added. The slighly orange colored precipitate was then filtered off. The residue was dried at 50C under vacuum for 16 hours and 122 g of 2,4 bis-(N-methyl-4-pyridylium)-striazine bis tribromide F 25 3255C was thus obtained.

It is also possible to manufacture the following compounds by one of the methods indicated in Examples 1 to 9:

Melting Point Compound Refractive Index 2,4-bis-( N '-methyllium )-s-triazine-dichloride 210 (decomp) 2.4-his-lN-allyl-4 pyridylium) 70-80 (decomp) -s-triazine-dichloride 125 (decomp.)

-6-methyl-s-triazine-diiodide Compound ll(dccomp.) Melting Point 2 .4-bis-( N '-isopropyl4'-pyridylium) -6-mcthyl-s-triazine-diiodide 2.4-bis-( N -n-octy1-4-pyridylium -6-methyl-striazine-diiodidc 2.4-bis-( N '-methyl-4'-pyridylium) -s triazinc-dichloridc 2.4-bis-N '-methyl-4 '-pyridiliums-triazine-dibromidc 225 (decomp) 160 (decomp) The technical applicability of the new quaternary salts is based on their growth regulating properties which produce increases in yield or quality in the crop products of the useful plants or which help facilitate harvesting. The bis(pyridylium)-s-triazines of the formula l are particularly suitable for the defoliation or desiccation of parts of plants above the soil in individual plant species, e.g. in cotton, leguminous plants, sorghum, soya, potatoes, vines; or they are also suitable for the defoliation of shrubs or trees which are destined for dispatch. In low rates of application the compounds effect an abscission of fruit such as citrus fruit, cherries, vines, damsons, berries, nuts. A further property is the favourable regulation of the storage capacity of vegetable matter contained in plants and the concomitant prevention of the premature degradation of such matter. As an example there may be cited the increase in the starch content in potato tubers or the increase in the sugar content in sugar beet or sugar cane. Particular mention is to be made of the ripening of sugar cane, in which the unwanted degradation of sucrose is prevented in connection with the suppression of the new shoots of plant parts. The compounds of the formula 1 also posses selective herbicidal action, above all as contact herbicides.

The diversity of the plant growth regulation is illustrated by the following Examples.

EXAMPLE 10 Defoliation of Cotton Plants An active substance solution (about 5%) was sprayed in a rate of application of 1 kg, 0.5 kg and 0.25 kg per hectare on a strip of cotton field with 80% of opened capsules. As comparative substances there were used the known commercial defoliants DEF (=trin-butyl-trithiophosphate), Folex (=tri-N-butyl-trithiophosphite) and the compound 2,5-bis (N"-methyl-4"- pyridinium)-1,3,4-thiadiazole-diiodide (known from French Pat. No. l.547,531) of the formula A The 1st and 2nd evaluation took place after 7 and 14 days and yielded the following result:

-Continued -Continued Compound Evaluation after kg.AS/ha 7 days 14 days Concentra- Pctioles 7 1 Compound tion of acshed I, 5 tivc suhafter Folex 3:6 stancelppni] 3 days 4 days 0.5 7 l dylium )-s-triazine-dibromidc 2000 l4 16 0.25 7 Z 2.4-bisl N -n-propyl-4'-pyri- 4000 4 12 A 1.0 4 2 dylium )-striazine-diiode 2000 2 s 0.5 7 3 2.4-bis( N mcthyl-4-pyri- 4000 i 2 16 0.25 9 3 l0 dylium)-s-trialinc-dichloridc 2000 8 13 Rating: 9 0 to l 17: defoliation 8 l2 to 22/7: defoliation 7 23 to 33% defoliation l=8'-) l007ldfl' i m e 5 Application to Sugar Cane Fifteen 21 to 24 months old sugar cane plants were EXAMPLE l 1 each treated with an aqueous active substance solution. D i i f Potato Pl The solution with 38 mg of active substance per plant In two parallel tests plots measuring 2.5 X m with (:35 kg of fictive was Introduced (names of the variet Binfen which were 2 3 weeks the leaf rachises. Harvesting took place after 4 weeks p y in one test. after 5 weeks in the other. The influence of from being ripe for harvesting, were sprayed with acthe active substance on the sugar content was detertive substance solution. The application was carried out d b h d I H h b 000 mine y measuring t e presse julCC po arimetrica y wit a out 1 itres of spray broth per hectare in rates of application of 5 g 2 5 g and l 25 k er and in comparison with the press JUICe of untreated hectare The commercial de'siccam 2 rheth 25 plants. The active substance 2,3.6-trichlorobenzoic y acid, known from US. Pat. No. 3.245.775 and recomdinitroplienol (=DNOC) was used as comparative mended for treating sugar cane, was used as comparacompound. The 1st and 2nd evaluation took place after five Subsnnce 7 and 14 days yielded the following result:

Evalumk" after Compound Sugar content in pressed juice kg AS/ha 7 days 14 days an 4 weeks 5 weeks 2.4-bistN-ethyl:4'-pyridylium) 5.0 4.5 l i 2.4-bis(N'-methyl-4'-pyridy- 9.8 '7 10.9 it

, l lium)-s-triazine-diiodidc -0 0 P m -Pyndyhum) l 2.3.6-trichlorobenzoic acid 9.3 v. 10.2 7 smazme'dlbromlde 3' 5 untreated control 8.8 8.8 7( DNOC 5:0 4 2" 2.5 8 5.5

Rating: 40 14 I plants above the soil completely desiccated 3mm .Plots in cotton fields in Mississippi, USA and in Spain 3 3="Immediatestagesttfdcsiccminn were sprayed with a solution containing 5 and 2,5 kg per hectare of test substance. when the field had 70 to EXAMPLE I2 80% of opened bolls. The evaluation took place after two weeks and the rate of defoliation (def) and dessica- Cmus absclsslon tion (dess) is expressed in percenit as compared to Citrus sinensis plants were raised in pots in a greenm not treated Plals in the Same COIIOH fi house. After the cultivation. branches about 35 cm The results are given the table below long were cut off from which all the foliage and the majority of the petioles were removed. so that the branch C d k Mm s only bore 8 petioles. Two branches were sprayed with mpmm Asfna 332 Pam an active substance concentration and individually def dcss def (less I 1 I 1 1 o placed in an Erlenmeyer flask with ma ns water at 21 C 5 75% 35% In and relative humidity in a conditioning cabinet. 55 pyridliliumgmuinc. 15 0; The branches were exposed to about 10.5 hours of light Q 21 h '4 s 907 Wz In W l t. per day (about 20.000lux). Evaluation ofthe abscission :t l, 25 5% of the 16 petioles per active substance concentration di-mcthosulfatc a took place after 3 and 4 days and permitted a direct 4 5 99% conclusion to be drawn with regard to the abscissioii of 60 0% citrus f i giygli girliiptmys-triazinc- 2.5 7071 I571 83'71 2.4-his-(N'-nicthyl-4' 5 x5 30; 0% in pyridiliuml-s-triazinc- 2.5 7571 20' 1 S7: 45% di-fluorosulfatc Cunccmm pmiolcs l.4-his-(N'-mcthyl4- 5 65' v; I071 09'); cmnpmmd mm of L, Shcd 6s pyridiliunil-s-tri:i/ine- 2.5 800; 95' NW; 08%

live suh- :iltcr d'chlmdc smncclppml 3 days 4 days 2.4- his -(N'-mclliyl-4'- 5 X07; 9502 20'); 9371 pyrid lium lfwll'lilllflt" 2 5 5'4 I0"; 25'? 53: 14mm NumclhyldupyrL 4mm 5 1h hist trihi'omidc) (y; O 0,); W4

control (untreated) The agents according to the invention contain either the new active substances alone or in combination with other biocidal active substances. In this way it is possible to broaden and improve their activity spectrum and to adapt it to given circumstances. Preferably, the agents according to the invention contain in addition active substances which are suitable for defoliation, desiccation and as contact herbicide. The new agents can therefore contain, for example, the following compounds with dcfoliating and/or desiccating action:

Inorganic compounds calcium caynamide, sodium cyanamide, cyanamide, sodium chlorate, mixture of sodium chlorate and ammonium hydrogen phosphate, magnesium chlorate, potassium iodide, sodium iodide, ammonium nitrate, urea, sodium arsenite, arsenic trioxide, cacodylic acid, alkali or ammonium thiocyanate.

Alcohols, phenols and ethers l,4-butindiole, Z-butylthiobenzthiazole, 2- vinylthiobenzthiazole, 2-heptylthiobenzthiazole, 2,4- dinitro-6-sec.butylphenol, pentachlorophenyl, 4-hydroxybenzenesulphonyl fluoride, hexafluoroacetone, l-methyl-4-chlorobenzimidazolone, 4-isothiocyano-dimethylaniline, N,N'-ethylenedipyridilium salts, N,N-ethylene-dipyridilium salts, B-chloro-acrylic acid, B-trichloroacetyl-a, B-dichloroacrylic acid, undecylenic acid, dithio-bis(O-ethyl-thionoformiate), dithio-bis-(O-methylthionoformiate), 7-oxahydro- [2,2,1]-heptane-2,3-dicarboxylic acid and salts thereof, sodium ethylxanthate, N,N-diethyl-S-(diethyl amino-thiolo-phosphoric diamide, tris-butylthiophosphine, S,S,S-trisbutyltrithio-phosphoric acid, B-chloroethybphosphonic acid.

Furthermore, it is also possible for the new agents to contain contact herbicides from the following classes of compounds:

carbamates, thiolcarbamates, dithiocarbamates, ureas, thioureas, isoureas, xanthogenic acid derivatives, aliphatic carboxylic acids, salts and esters thereof, aromatic carboxylic acids, salts and esters thereof, phenoxycarboxylic acids, salts and esters thereof, carboxylic amides, anilides and thioamides, nitriles, phenols, phenolates, phenyl ester, diphenyl ether, pyridine derivatives, dipyridylium salts, pyridazone derivatives, uracil derivatives, imidazole and benzimidazole derivatives, thiazole and benzthiazole derivatives, triazine derivatives, thiadiazole and benzthiadiazole derivatives, oxidazine and thiadiazine derivatives, oxdiazole derivatives, chlorinated hydrocarbons, alcohols, aldehydes, ketones, nitroanilines, other quaternary salts, sulphonic acid derivatives, phosphorus compounds, inorganic compounds.

The agents according to the invention are manufactured in known manner by intimately mixing and/or grinding active substances of the formula I with the suitable carriers, optionally with the addition of dispersants or solvents which are inert towards the active substances. The active substances may take and be used in the following forms:

Solid forms:

dusts, tracking agents, granules, coated granules, impregnated granules and homogeneous granules.

Liquid forms:

a. active substances which are dispersible in water: wettable powders, pastes, emulsions:

b. solutions.

To manufacture solide forms (ducts, tracking agents), the active substances are mixed with solid carriers. Suitable carriers are, for example: kaolin, talcum, bolus, loess, chalk, limestone, ground limestone, attaclay, dolomite, diatomacous earth, precipitated silica, alkaline earth silicates, sodium and potassium aluminium silicates (feldspar and mica), calcium and magnesium sulphates, magnesium oxide, ground synthetic materials, fertilisers, for example ammonium sulphate, ammonium phosphate, ammonium nitrate, urea, ground vegetable products, such as corn meal, bark dust, sawdust, nutshell meal, cellulose powder, residues of plant extractions, activated charcoal etc. These substances can either be used singly or in admixture with one another.

The particle size of the carriers for dusts is advantageously up to 0.1 mm, for tracking agents from about 0.075 to 0.2 mm, and for granules 0.2 mm or larger.

The solid forms contain the active substances in concentrations from 0.5 to

To these mixtures can also be added additives which stabilize the active substance and/or non-ionic, anionic and cationic surface active substances, which for example improve the adhesion of the active ingredients on plants or parts of plants (adhesives and agglutinants) and/or ensure a better wettability (wetting agents) and dispersibility (dispersing agents). Examples of suitable adhesives are the following: olein/chalk mixture, cellulose derivatives (methyl cellulose, carboxymethyl cellulose), hydroxyethyl glycol ethers of monoalkyl and dialkyl phenols having 5 to 15 ethylene oxide radicals per molecule and 8 to 9 carbon atoms in the alkyl radical, lignin sulphonic acids, their alkali metal and alkaline earth metal salts, polyethylene glycol ethers (carbowaxes), fatty alcohol polyethylene glycol ethers having 5 to 20 ethylene oxide radicals per molecule and 8 to 18 carbon atoms in the fatty alcohol moiety, condensation products of urea and formaldehyde, and also latex products. Preferred dispersions (suspensions and emulsions) are manufactured by mixing or grinding the active substances with carriers accompanied by the addition of dispersing agents and solvents, in the process of which there result firstly dispersible active substance concentrations, such as wettable powders and emulsifiable concentrates.

The water-dispersible concentrates of the active substance i.e.. wettable powders, pastes and emulsifiable concentrates, are agents which can be diluted with water to any concentration desired. They consist of active substance, carrier, optionally additives which stabilize the active substance, surface-active substances and anti-foam agents and, optionally, solvents. The active substance concentrations in these agents are from 5 80%.

wettable powders and pastes are obtained by mixing and grinding the active substances with dispersing agents and pulverulent carriers in suitable apparatus until homogeneity is attained. Carriers are, for example, those mentioned for the solid forms of application. In some cases it is advantageous to use mixtures of different carriers. As dispersing agents there can be used, for example condensation products of sulphonated naphthalene and sulphonated naphthalene derivatives with formaldehyde, condensation products of naphthalene or napthalene sulphonic acids with phenol and formaldehyde, as well as alkali, ammonium and alkaline earth metal salts of lignin sulphonic acid, in addition, alkylaryl sulphonates, alkali and alkaline earth metal salts of dibutyl napthalene sulphonic acid, fatty alcohol sulphates such as salts of sulphated hexadecanols, heptadecanols, octadecanols, and salt of sulphated fatty alcohol glycol ethers, the sodium salt of olcoyl, the sodium salt of olcoyl methyl tauride, ditertiary acetalene glycols, dialkyl dilauryl ammonium chloride and fatty acid alkali and alkaline earth metal salts.

Suitable anti-foam agents are silicones.

The active substance is so mixed, ground sieved and atrained with the additives mentioned above that, in wettable powders, the solid particle size of from 0.02 to 0.04 and in pastes, of 0.03 is not exeeded. To produce emulsifiable concentrates and pastes, dispersing agents such as those given in the previous paragraphs, organic solvents and water are used. Examples of suitable solvents are the following: alcohols, benzene, xylenes, toluene, dimethyl sulphoxide, and mineral oil fractions boiling between 120 and 350C. The solvents must be practically odorless, not phytotoxic, inert to the active substances and not readily inflammable.

Furthermore, the agents according to the invention can be applied in the form of solutions. For this purpose the active substances or several active substances of general formula II are dissolved in suitable organic solvents, mixtures of solvents or in water. Aliphatic and aromatic hydrocarbons, chlorinated derivatives thereof, alkyl naphthalenes and mineral oils singly or in admixture, can be used as organic solvents. The solu tions contain the active substance in a concentration range from 1 to In addition to fungicidal active substances, the agents described according to the invention can be mixed with other biocidally active substances or agents. Thus in order to broaden the activity spectrum the new agents may contain, for example, insecticides, fungicides, bactericides, fungistatics, bacteriostatics or nematocides, in addition to the cited active substance of the formula I. The agents according to the invention may also contain plant fertilisers, trace elements etc.

The active substances of the formula I can, for example, be formulated as follows. The parts denote parts by weight.

Powder Concentrate wettable Powder The following constituents are used to manufacture (a) a 50%, (b) a and (c) a 10% wettable powder:

50 parts of 2,4-bis-(Nethyl-4-pyridylium)-s-triazinediiodide,

5 parts of sodium dibutylnaphthalene sulphonate,

b 3 parts of naphthalenesulphonic acid/phenolsulphonic acid/formaldehyde condensate (3:2:1

20 parts of kaolin,

22 parts of Champagne chalk;

25 parts of 2,4-bis-(N-methyl-4-pyridylium)'s-triazine-diiodide,

5 parts of sodium oleylmethyltauride,

2.5 parts of naphthalenesulphonic acid/formaldehyde condensate,

0.5 part of carboxymethyl cellulose,

5 parts of neutral potassium aluminium silicate,

62 parts of kaolin;

l0 parts of 2,4-bis-(N'-methyl-4'-pyridylium)-striazine-dichloride,

3 parts of a mixture of the sodium salts of saturated fatty alcohol sulphates,

5 parts of naphthalenesulphonic acid/formaldehyde condensate,

82 parts of kaolin.

The indicated active substance is applied to the corresponding carriers (kaolin and chalk) and then these are mixed and ground, to yield wettable powders of excellent wettability and having an excellent capacity for forming suspensions. By diluting these wettable powders with water it is possible to obtain suspensions of every desired concentration of active substance.

Paste The following substances are used to manufacture a 45% paste:

45 parts of 2,4-bis-(N'-methyl-4-pyridylium)-s-triazine-diiodide,

5 parts of sodium aluminium silicate,

14 parts of cetyl polyglycol ether with 8 mols of ethylene oxide,

1 part of oleyl polyglycol ether with 5 mols of ethylene oxide,

2 parts of spindle oil,

l0 parts of polyethylene glycol,

23 parts of water.

The active substance is intimately mixed with the addition in appropriate devices and ground. A paste is obtained from which, by diluting it with water, is possible to manufacture suspensions of every desired concentration of active substance.

Emulsion Concentrate To manufacture a 25% emulsion concentrate 25 parts of 2,4-bis(N'-ethyl-4'-pyridylium)-s-triazinedibromide,

5 parts of a mixture of nonylphenolpolyoxyethoxyethylene and calcium, dodecylenesulphonate,

35 parts of 3,5,5-trimethyl-2-cyclohexan-l-one,

35 parts of dimethyl formamide,

are mixed together. This concentrate can be diluted with water to give emulsions in desired concentrations.

17 18 I claim: 5. A composition for regulating the growth of plants 1. A composition for regulating the growth of plants which comprises (1) as active ingredient a compound which comprises (1) as active ingredient an effective of the formula amount of a compound of the formula /N a N T R3 r in which R is hydrogen, alkyl of from 1 to 8 carbon atoms, haloalkyl of from 1 carbon atoms, NH OH, phenyl, 4-pyridyl or N'-methyl-4-pyridylium; each of R and R independently represents alkyl of from l to in which is hydrogen alkyl of from 1 to 8 carbon 8 carbon atoms, alkenyl of from 3 to 7 carbon atoms, flt0m$- haloalkyl 9 from 1 to 4 z haloalkyl of from 1 to 4carbon atoms, alkylthio of from OH, P y 'Pl y 0T y PY" Y each l to 4 carbon atoms, cyano or alkoxycarbonyl wherein of R and R independently represents alkyl of from I the alkoxy moiety has from 1 to 4 Carbon atoms; and to 8 Carbon atoms, alkenyl of from 3 to 7 Carbon atoms X is a trivalent halogen anion selected from the group haloalkyl of from 1 to 4 carbon atoms, alkoxy of from consisting 0H3, Bra, BrZC], 1213f and 1; and 2 a 1 to 4 carbon atoms, alkylthio of from 1 to 4 carbon den 8I0m5- cyano or alkoxycarbonyl in which the alkoxy 3O 6. A composition according to claim 5 in which the moeity has from 1 to 4 carbon atoms; and X is the compound is anion of an acid selected from the group consisting of hydrochloric, hydrobromic, hydroiodic, phosphoric, thiophosphoric, sulphuric, fluoroboric, perchloric, methylsulphuric, ethylsulphuric, benzenesulphonic, p-toluenesulphonic, naphthoic, benzoic, halobenzoic,

acetic, haloacetic, aminoacetic, propionic, halopro- 3 N pionic,butyric,lactic,stearic,oxalic,tartaric and fluro- 2| Gf N I 2 X (-D sulphuric; and (2) a carrier. 2

2. A composition according to claim 1 in which the compound is in which R,4O is hydrogen or alkyl of from 1 to 4 carbon atoms; R is alkyl of from 1 to 4 carbon atoms; and R -N N I 2 X G x is tribromide or triiodide.

2 N N 2 7. The composition according to claim 6 in which the compound is 2,4-bis(N-methyl-4-pyridylium)-s- I triazine bis(tribromide). I 8. A method for improving the yield and facilitating the harvesting of crops which comprises applying to a crop culture, in an amount sufficient to regulate plant growth, a compound of the formula in which R, is hydrogen or alkyl of from 1 to 4 carbon atoms; R is alkyl of from 1 to 4 carbon atoms; and X is chloride, bromide, iodide, methosulphate or fluorosulphate. N 63 e 3. A composition according to claim 2 in which R, W N R 2 X is hydrogen or methyl and R is methyl or ethyl 65 4. The composition according to claim 3 in which the N N compound is 2,4-bis(N'-methyl-4'-pyridylium)-striazine dibromide. R

in which R is hydrogen, alkyl of from 1 to 8 carbon atoms, haloalkyl of from 1 to 4 carbon atoms, NH OH, phenyl, 4-pyridyl or N'-methyl-4-pyridylium; each of R and R independently represents alkyl of from 1 to 8 carbon atoms, alkenyl of from 3 to 7 carbon atoms, haloalkyl of from 1 to 4 carbon atoms, alkoxy of from 1 to 4 carbon atoms, alkylthio of from 1 to 4 carbon atoms, cyano or alkoxycarbonyl in which the alkoxy moiety has from 1 to 4 carbon atoms; and X is the anion of an acid selected from the group consisting of hydrochloric, hydrobromic, hydroiodic, phosphoric, thiophosphoric, sulphuric, fluoroboric, perchloric, methylsulphuric, ethylsulphuric, benzenesulphonic, p-toluenesulphonic, naphthoic, benzoic, halobenzoic, acetic, haloacetic, aminoacetic, propionic, halopropionic, butyric, lactic, stearic, oxalic, tartaric and fluorosulphuric; and (2) a carrier.

9. A method according to claim 8 in which the compound is in which R, is hydrogen or alkyl of from 1 to 4 carbon atoms; R is alkyl of from 1 to 4 carbon atoms; and X is chloride, bromide, iodide, methosulphate or fluorosulphate.

10. A method according to claim 9 in which R is hydrogen or methyl and R is methyl or ethyl.

11. The method according to claim 10 in which the compound is 2,4-bis(N'-methyl-4'-pyridylium)-striazine dichloride.

12. The method according to claim 10 in which the compound is 2,4-bis(N-methyl-4'-pyridylium)-striazine dibromide.

13. The method according to claim 10 in which the compound is 2,4-bis(N-methyl-4-pyridylium )-striazine diiodide.

14. The method according to claim 10 in which the compound is 2,4-bis(N'-methyl-4 pyridylium)-striazine fluorosulphate.

15. The method according to claim 10 in which the compound is 2,4-bis(N'-ethyl-4'-pyridylium)-s-triazine diiodide.

16. The method according to claim 9 in which the compound is 2,4-bis(n-n-propyl-4-pyridylium)-striazine diiodide.

17. The method according to claim 10 in which the compound is 2,4-bis(N-methyI-4-pyridylium)-6- methyl-s-triazine diiodide.

IS. The method according to claim 10 in which the compound is 2,4-bis(N'-methyl-4'-pyridylium)-striazine bis(methosulphate).

19. A method for improving the yield and facilitating the harvesting of crop culture which comprises applying to a crop in an amount sufficient to regulate plant growth, a compound of the formula in which R is hydrogen, alkyl of from I to 8 carbon atoms, haloalkyl of from 1 to 4 carbon atoms, NH OH, phenyl, 4-pyridyl or N-methyl-4-pyridylium; and each'of R and R independently represents alkyl of from l to 8 carbon atoms, alkenyl of from 3 to 7 carbon atoms, haloalkyl of from 1 to 4 carbon atoms, alkylthio of from 1 to 4 carbon atoms, cyano or alkoxycarbonyl wherein the alkoxy moiety has from I to 4 carbon atoms; and X is a trivalent halogen anion selected from the group consisting of 1 Br Br Cl, l Br and Br l.

20. A method according to claim 19 in which the compound is triazine bis(tribromide).

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,901,678 Dated August 26, 1975 Inventor) Hanspeter Fischer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In column 18, claim 5, line 6 (counting the structural formula as one line) the line should read:

atoms, haloalkyl of from 1 to 4 carbon atoms, NH OH,

In column 18, claim 6, line 4 I (Counting the structural formula as one line) the line should read:

in which R is hydrogen, alkyl of from 1 to 4 car- Signcd and Scaled this twenty-third Day of December1975 [SEAL] A ttest:

RUTH C. MASON C. MARSHALL DANN Arresting Office Commissioner ofPatents and Trademarks 

1. A COMPOSITION FOR REGULATING THE GROWTH OF PLANTS WHICH COMPRISES (1) AS ACTIVE INGREDIENT AN EFFECTIVE AMOUNT OF A COMPOUND OF THE FORMULA
 2. A composition according to claim 1 in which the compound is
 3. A composition according to claim 2 in which R1'' is hydrogen or methyl and R2'' is methyl or ethyl.
 4. The composition according to claim 3 in which the compound is 2,4-bis(N''-methyl-4''-pyridylium)-s-triazine dibromide.
 5. A composition for regulating the growth of plants which comprises (1) as active ingredient a compound of the formula
 6. A composition according to claim 5 in which the compound is
 7. The composition according to claim 6 in which the compound is 2,4-bis(N''-methyl-4''-pyridylium)-s-triazine bis(tribromide).
 8. A method for improving the yield and facilitating the harvesting of crops which comprises applying to a crop culture, in an amount sufficient to regulate plant growth, a compound of the formula
 9. A method according to claim 8 in which the compound is
 10. A method according to claim 9 in which R1'' is hydrogen or methyl and R2'' is methyl or ethyl.
 11. The method according to claim 10 in which the compound is 2, 4-bis(N''-methyl-4''-pyridylium)-s-triazine dichloride.
 12. The method according to claim 10 in which the compound is 2, 4-bis(N''-methyl-4''-pyridylium)-s-triazine dibromide.
 13. The method according to claim 10 in which the compound is 2, 4-bis(N''-methyl-4''-pyridylium)-s-triazine diiodide.
 14. The method according to claim 10 in which the compound is 2, 4-bis(N''-methyl-4''-pyridylium)-s-triazine fluorosulphate.
 15. The method according to claim 10 in which the compound is 2, 4-bis(N''-ethyl-4''-pyridylium)-s-triazine diiodide.
 16. The method according to claim 9 in which the compound is 2, 4-bis(n''-n-propyl-4''-pyridylium)-s-triazine diiodide.
 17. The method according to claim 10 in which the compound is 2, 4-bis(N''-methyl-4''-pyridylium)-6-methyl-s-triazine diiodide.
 18. The method according to claim 10 in which the compound is 2, 4-bis(N''-methyl-4''-pyridylium)-s-triazine bis(methosulphate).
 19. A method for improving the yield and facilitating the harvesting of crop culture which comprises applying to a crop in an amount sufficient to regulate plant growth, a compound of the formula
 20. A method according to claim 19 in which the compound is
 21. The method according to claim 20 in which the compound is 2, 4-bis(N''-methyl-4''-pyridylium)-s-triazine bis(triiodide).
 22. The method according to claim 20 in which the compound is 2, 4-bis(N''-methyl-4''-pyridylium)-s-triazine bis(tribromide). 